motor for lathe

[petertha]

Dealerselectric for me too, and even though I'm in Canada they still were the best price. I've bought from them 2 times now (vfd for mill and vfd and motor for lathe).
Mike

My motors are still in good shape but the speed variability of VFD & especially slower speeds is something I would really enjoy when the day comes. Maybe sooner based on those prices.

Dumb question, but after swapping in motor/vfd on gearhead mills & lathes, do you just park in a midrange gear & control rpm through the blinky light box thereafter? Or maybe you can change gears the same way & this gives you even more rpm control options over stock fixed rpm motor?

Also, are there any VFD issues or considerations to lathes that power on with the typical handle switch on the carriage? I thought someone mentioned you cant just turn VFD's 'on' like that or you needed a particular flavor.

 

[ninefinger]

In general I tend to use my lathe as I did before; pick the right gear range for the surface speed of what you are wanting, but you can twiddle the speed to improve the cut if there is something going on at the particular speed you picked. I've since started picking gears with my starting speed at ~ 40Hz an increasing to 60 or 70Hz as I get to smaller diameters to help keep the cutting speed the same as it was to begin (or closer anyway).
For the mill I'm a rank amateur (lathe too BTW), so I've pretty much done as above but the surface cutting speed doesn't vary as you go so I just adjust to find a nice surface finish.

As for turning on - yes - you no longer switch the AC to operate the motor. You give signals to the VFD. So for my lathe I have a disconnect to the VFD, and I repurposed the Forward/off/Reverse switch to signal the VFD. See the pics I took. For the mill the same idea till I get the PC controlling the spindle (the mill is CNC now), however the control panel is a home made solution with:
1. Variable speed pot,
2. Forward / stop / reverse switch
3. E-stop connected into VFD as an input as well
4. The "start" button acts as a reset for the VFD if the e-stop is pressed or it faulted.

Hope that helps a bit
Mike
PS: writing this reminded me that I've intended to but not got around to installing an E-stop for the lathe at a spot down low in front of the carriage - MUST FIX (note to self)
PPS: I needed to add the vfd to the lathe as it came with a ~530 volt 3 phase motor that I could not power in my shop so conversion to something else was a necessity, and the vfd and 3 phase motor just made good sense. The mill I bought with the 3 phase motor as an option for not much money so the vfd for it wasn't to cost prohibitive...(I recouped some money on the sale of the single phase motor too..)

 

[zetuskid]

I use treadmill motors for all my repowering needs. People practically give them away. They are upwards of 2.5HP and you can strip the DC controller out of the treadmill and us it. it works great. I can send you some pic and instructions how to hook it up if you like

If the offer is still available, I would appreciate having done simple wiring directions on wiring the treadmill motor for the lathe. I have the motor and power controller but would like information on hooking up a tachometer and heat thermometer to the motor.
Thanks
zetuskid

 

[stragenmitsuko]

There's a book in the workshop practice series about electric motors , what to look for and what not .
Could be handy if you don't know much about electric motors .

I would definitly agree , a 3 phase motor and a vfd are the best choice .
Most junkyards will have a motor section , and you should be able to pick up
a small 3 phase for little money .

Pat